Staging Soybeans –R stage Critical Considerations

Del Voight Penn State Extension

Many fields of soybeans are actively growing and there some general information one needs to become familiar with what the plant is going through at this time.  Many fields at this time are in the R2 growth stage.  What does this mean? R2 is identified by first inspecting for the presence of  the flowers.Once flowers are observed within the top 2 nodes of the top  of the plant(full flower) the plant is in the R 2 stage.   Plants have two main stages V and R. The V stands for vegetative that is to say the stage that the plant germinates emerges and puts leaves on the main stem. Then the R stage which refers to the reproductive stage.  This stage marks a change in the plant from  simply growing green leaves to begin to prepare the metabolism and prepare to produce an ear or a pod.  In many cases both stages exist with Soybeans they will continue to put new leaves on while flowering.  Typically they will stay in the V stages for about 40 days or more.  Once in the R stage the plant will stay in R stages until harvest.


Most fields should be in the R2 stage.  Now you know what I am referring to pertaining to stages.  At this stage the flowers are self pollinating.  The pods are being formed within the flower.   Inter canopy humidity and temperature will now factor into whether the pod forms and aborts.    The plants 300 bu/acre potential is now being dictated by temperature, pest pressure,  stress from drought or water.  Typically 60-75% of the total flowers fail to produce a pod.  The plant will stay in the flowering condition for a 30 day period but will move from R2-R3 in about 2 weeks. R3 is marked by the formation of a pod that is 3/16th of an inch at any of the top 4 nodes. The top third of the soybean leaves directly impact yield.  Therefore scouting is required to ensure limited damage from insect or disease.

Penn State Extension and Soybean Board funding of field research has been working on determining benefits of fungicides applied at  R3 to date the data suggest that  applications of fungicides average a return to the application of about 3-4 bu/acre. 
 Consider applications If there is visible disease and the weather in the two week forecast is wet and high humidity benefits might be greater than  if conditions remain dry and low humidity.Also realize that wheel traffick will reduce yields based on boom width.  Wider booms have less impact. For instance Ohio State Extension engineers have shown about a 2.5 bu/acre loss with a typical 45 foot boom and a 1.5 bu/acre loss with a 90 foot boom. Wheel width also may reduce the impact of trafficking in the soybeans.  Consider custom applications if wider boom width is not available on your farm.  Check for the presence of soybean aphids, stink bugs, bean leaf beetles and grasshoppers to ensure that they will not reduce soybean canopy by R3 to ensure yield is protected through the pod filling stages.  Check the Agronomy Guide for Pesticide options, rates and application specifications.

Downed Cherry Trees Pastured cattle concerns after wind damage

With so many cherry trees that have blown over with the recent floods as cattle are put back into these environment be advised that those cherry leaves once wilted may contain cyanide. I have talked to several veterinarians and have found that once the leaves have fallen off the plant the cyanide levels will drop. However if the leaves are still connected to the plant stems the leaf tissue can draw toxins from the branches into the leaves.  Many factors lead to the breakdown of cyanide through hydrolosis and that will depend on many factors most notably if the leaves are still connected to the branches. They are recommending to clean the trees out ASAP and get as much of the dropped leaves off the ground before commencing grazing activities.
I have personally been involved in  cases where several large dairy cows were killed by eating the leaves of cherry.  Pretty simple to diagnose since the cherry tree was down in the dry cow lot and you could see the hoof prints. The lab test came back to confirm so watch out.  Another case was with Ewe bushes that several young stock were killed by consuming the plants. The producer had fenced off a section around an abandoned home which had the ewe bushes and the cattle in there were dead in a week. Necropsy also confirmed.
Here is a factsheet that details the issue. I have some cherry that had gone down and I cleaned up as much as I could then turned the cattle out. I had thought I had removed most cherry trees but missed a couple and sure enough they were the ones to go over.  Once you cut the stump you need to apply the stump treatment before the tissue dries can be minutes in dry weather. A great reference for stump treatments from Florida State University is here http://edis.ifas.ufl.edu/ag245.

Cut Stump
Imazapyr
(Arsenal AC or Stalker)
6 oz/gal (for Arsenal AC)
or
8-16 oz/gal (for Stalker)
Apply to the top and side of a freshly cut stump. Garlon 3A is excellent for this use. If surface of stump has began to dry prior to herbicide treatment, apply Chopper, Garlon 4, Remedy or Pasturegard in basal oil – or recut the stump and apply the freshly cut surface. Garlon 3A will not effectively mix with basal oils.
Triclopyr
(Garlon 3A)
50 – 100% in water
Triclopyr
(Remedy Ultra or Garlon Ultra)
25% solution in water or basal oil
Triclopyr + fluroxypyr
(Pasturegard)
50% solution in water or basal oil
Glyphosate
(several)
50-100%
Apply to cut stumps immediately after cutting. Glyphosate is not effective on stumps that have started to dry after cutting. If immediate treatment is not possible, other herbicides should be selected since glyphosate will not mix with basal oils.
Cut Stump
Imazapyr
(Arsenal AC or Stalker)
6 oz/gal (for Arsenal AC)
or
8-16 oz/gal (for Stalker)
Apply to the top and side of a freshly cut stump. Garlon 3A is excellent for this use. If surface of stump has began to dry prior to herbicide treatment, apply Chopper, Garlon 4, Remedy or Pasturegard in basal oil – or recut the stump and apply the freshly cut surface. Garlon 3A will not effectively mix with basal oils.
Triclopyr
(Garlon 3A)
50 – 100% in water
Triclopyr
(Remedy Ultra or Garlon Ultra)
25% solution in water or basal oil
Triclopyr + fluroxypyr
(Pasturegard)
50% solution in water or basal oil
Glyphosate
(several)
50-100%
Apply to cut stumps immediately after cutting. Glyphosate is not effective on stumps that have started to dry after cutting. If immediate treatment is not possible, other herbicides should be selected since glyphosate will not mix with basal oils.
Cut Stump
Imazapyr
(Arsenal AC or Stalker)
6 oz/gal (for Arsenal AC)
or
8-16 oz/gal (for Stalker)
Apply to the top and side of a freshly cut stump. Garlon 3A is excellent for this use. If surface of stump has began to dry prior to herbicide treatment, apply Chopper, Garlon 4, Remedy or Pasturegard in basal oil – or recut the stump and apply the freshly cut surface. Garlon 3A will not effectively mix with basal oils.
Triclopyr
(Garlon 3A)
50 – 100% in water
Triclopyr
(Remedy Ultra or Garlon Ultra)
25% solution in water or basal oil
Triclopyr + fluroxypyr
(Pasturegard)
50% solution in water or basal oil
Glyphosate
(several)
50-100%
Apply to cut stumps immediately after cutting. Glyphosate is not effective on stumps that have started to dry after cutting. If immediate treatment is not possible, other herbicides should be selected since glyphosate will not mix with basal oils.

So take a small sprayer and pre mix have it ready when you cut the final stump then treat it immediately.  Here is a complete write up of the situation.

Cherry Poisoning

Melissa Bravo had this to report pertaining to poisonous plants.

Wild black cherry, choke cherry, jetbead, peaches, plums, apples, apricots, almonds (Prunus Family)
The prunus family contains many plants have may have poisonous parts to both livestock and humans. All plants parts including the pits and berries contain cyanide and HCN and discarding of ornamental and waste produce has lead to the death of livestock as well as those deaths associated with the grazing of these species in stressed pastures. Cyanide poisoning interferes with respiration and blood circulation; death is often swift (Kingsbury 1964, Cheeke 1983, Cheeke and Schull 1985). The lethal dose of HCN for cattle and sheep is about 2.0 mg/kg of body weight (Kingsbury 1964). Other signs of toxicity may include a short period of stimulation followed by slow pulse, dilated pupils, spasms, staggering, loss of consciousness, and death, which results from asphyxiation. Postmortem findings include bright red blood and congestion of internal organs (Kingsbury 1964, Scimeca and Oehme 1985).